A 3-amino-acid peptide (Lys-Pro-Val) derived from the C-terminal end of alpha-melanocyte-stimulating hormone (alpha-MSH). One of the most potent anti-inflammatory peptides known, with specific activity in the gut. Actively studied for inflammatory bowel disease.
KPV (Lys-Pro-Val) is a tripeptide corresponding to the C-terminal three amino acids (positions 11-13) of alpha-melanocyte-stimulating hormone (alpha-MSH). While alpha-MSH is primarily known for skin pigmentation, its anti-inflammatory properties have been recognized since the 1980s. KPV retains the full anti-inflammatory activity of alpha-MSH without the melanocortin receptor-dependent pigmentation effects.
KPV is particularly notable for its oral bioavailability — unusual for a peptide — and its specific activity in the gastrointestinal tract. It accumulates in inflamed colonic tissue, making it a promising candidate for treating inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis.
KPV is a tripeptide (Lys-Pro-Val) derived from the C-terminal end of alpha-melanocyte-stimulating hormone (α-MSH). While α-MSH is best known for its role in skin pigmentation (via MC1R activation), its C-terminal fragment KPV retains the anti-inflammatory properties without the melanogenic (tanning) effects. This separation of functions makes KPV attractive for inflammatory conditions where skin darkening would be an unwanted side effect.
KPV's primary target is the NF-κB pathway — the master transcription factor that controls expression of pro-inflammatory cytokines including TNF-α, IL-1β, IL-6, and IL-8. By inhibiting NF-κB nuclear translocation, KPV reduces inflammatory signaling broadly. This mechanism has been most extensively studied in the context of inflammatory bowel disease (IBD), where both oral and injectable KPV have shown promise in preclinical models of colitis.
KPV was placed on the FDA Category 2 list in late 2023 and is expected to return to Category 1 under the February 2026 HHS reclassification. See our March 2026 briefing for the latest status.
KPV's mechanism is distinct from other anti-inflammatory peptides because it acts intracellularly, not through cell surface receptors. After entering cells via the PepT1 peptide transporter, KPV directly inhibits the IKK-beta kinase that is required to activate NF-kB. Without IKK-beta activity, the inhibitory protein IkB-alpha remains bound to NF-kB, trapping it in the cytoplasm and preventing transcription of inflammatory genes.
| Pathway | Effect | Significance |
|---|---|---|
| NF-kB inhibition | Blocks IKK-beta phosphorylation, preventing NF-kB activation | Reduces transcription of pro-inflammatory cytokines |
| PepT1 uptake | Enters cells via peptide transporter upregulated in inflamed tissue | Preferentially accumulates in inflamed gut epithelium |
| Oral bioavailability | Survives GI transit as a small tripeptide | Can be taken orally for gut-targeted anti-inflammatory action |
| No melanocortin activity | Does not bind MC1R-MC5R receptors | No skin pigmentation or hormonal side effects |
| Antimicrobial | Direct antibacterial activity against S. aureus and Candida | May address microbial component of IBD pathogenesis |
| Study | Design | Findings | Level |
|---|---|---|---|
| Colitis models | Mouse DSS colitis | Oral and intraperitoneal KPV significantly reduced colonic inflammation, disease activity, and histological damage scores | Preclinical |
| NF-kB mechanism | In vitro, colonic epithelial cells | KPV inhibited NF-kB activation and IL-8 secretion in TNF-alpha-stimulated cells in a dose-dependent manner | Preclinical |
| Nanoparticle delivery | Mouse colitis | KPV-loaded nanoparticles targeted inflamed colon tissue with enhanced efficacy vs free KPV | Preclinical |
| Wound healing | In vitro + animal | Accelerated wound closure and reduced inflammation in skin wound models | Preclinical |
Preclinical safety: KPV has shown a favorable safety profile in animal studies with no reported toxicity at therapeutic doses. Its small size (just 3 amino acids) and naturally occurring origin (fragment of a human hormone) support its theoretical safety, though formal human safety studies are lacking.
No pigmentation effects: Unlike its parent molecule α-MSH, KPV does not activate MC1R at therapeutic concentrations and does not cause skin pigmentation changes — a significant advantage over full-length α-MSH analogs.
Oral bioavailability: KPV is being explored for oral administration, particularly for GI inflammatory conditions where local gut exposure may be therapeutically relevant. Its small size may facilitate intestinal absorption, though systemic bioavailability data is limited.
Limited human data: No human clinical trials have been completed for KPV. All efficacy and safety data comes from preclinical models. This represents a significant evidence gap despite the strong mechanistic rationale.
| Jurisdiction | Status |
|---|---|
| FDA | Not approved. Not reviewed. |
| Research | Active area of IBD drug development. Multiple nanoparticle delivery systems in development. |
| Availability | Available as a research peptide and in some functional medicine protocols |